1. Field of the Invention
This invention is related to an improved structure of an air compressor.
2. Description of the Prior Art
With reference to FIG. 10, the conventional air compressor includes an inverted L-shaped main frame 90 which is formed with a circular opening 901 at the horizontal portion for mounting a cylinder 91. The vertical portion of the main frame 90 is formed with an upper circular hole 902 for the passage of the front end of an electric motor 92 and a lower circular hole 903 for the passage of an axle 941 of a gear 94. The electric motor 92 is installed on the main frame 90 by extending screws 93 through the holes 904 to engage with the threaded holes 921 of the electric motor 92. The axle 941 is kept in place by a packing 95 and a C-shaped retainer 96. The gear 94 is meshed with a pinion 922 on the output axle of the electric motor 92. The gear 94 is provided with an eccentric pin 942 engaged with an outer end of the piston rod 97. As the electric motor is turned on, the pinion 922 will drive the gear 94 to reciprocate the piston within the cylinder for supplying compressed air via an outlet pipe 98. The cylinder 91 is fixedly mounted on the horizontal portion of the main frame 90 by screws 99. However, the vibration produced during the operation of the cylinder 91 will loosen the screws 99 thereby making the piston unable to move smoothly within the cylinder 91. Sometimes, the piston will be even locked in a fixed position within the cylinder 91. In addition, such an air compressor can only be used with a particular kind of nozzle thus limiting its usage.
Therefore, it is an object of the present invention to provide an improved structure of an air compressor which can obviate and mitigate the above-mentioned drawbacks.